CVS Flashcards
How do the LV and RV contract differently?
The LV contracts concentrically while the RV twists and contracts.
Afterload is also known as….
Wall tension across the ventricles at the end of systole.
P1: SVR (120)
P2: Pleural pressure (0-5)
T = [(P1-P2) x radius] divided by wall thickness. The smaller the delta P, the less the afterload. Lessen afterload by decreasing P1 (vasodilation) or increasing P2 (PEEP).
Preload is also known as…
Wall tension across the ventricle at the end of diastole. It generally represents the volume that stretches the ventricles before contraction.
What is a normal ejection fraction and what is a normal stroke volume?
EF = ESV/EDV (EF = 75/120, EF = 63%), normal EF = >60%
SV = EDV - ESV
Usually about 70mL in a 70kg male.
How does PPV affect the two ventricles?
To an extent, PPV props the LV up and decreases the pressure difference between the LV and intrathoracic space. This helps more than the detriment it causes to aortic compression so net benefit for the LV.
However, it also compresses the pulmonary vasculature and forces the RV to work harder, possibly decreasing LV preload. RV preload is already reduced due to great vessel compression.
*Generally speaking, PPV reduces CO, except in the case of high SVR.
Delta down must have a _____% change in order for a patient to be considered fluid responsive. They must be in sinus rhythm, paralyzed and be on a controlled tidal volume @10ml/kg for it to be considered accurate.
10
Murmur intensity is graded on a scale from 1-6. What grade is associated with a corresponding thrill?
4
1: only a cardiologist can hear
(6: you can hear that thing without a stethoscope!)
When describing a heart murmur, what characteristics are worth mentioning?
Shape (crescendo) Timing Location (A, P, T, M) Radiation (carotids, subclavians) Intensity (1-6)
Useful labs when assessing a CVS patient:
Troponins (HS, I, T) BNP Lactate SvO2 Extended lytes BUN:Cr CBC
There are five types of MI. What are they?
- Atherosclerosis
- Oxygen imbalance
- Sudden death
- PCI mediated
- CABG mediated
Standard therapy for NSTEMI pathway:
+ASA (162-325)
+P2Y12 inhibitors (Plavix 300/150, Ticagralor 180/90)
+Statins (Atorvastatin 80mg)
-Beta blockers (Metoprolol 5/25), or ACE-I if BP/HR high
-Nitrates (10mcg/min TNG infusion, TNG patch, TNG spray)
-Anticoagulation (Enoxaparin, heparin)
-O2/MSO4
-Optimize Mg++, K+
-Integrillin if there is a high clot burden
-Pantaloc 80mg bolus, then 8mg/hr infusion
Killip Score (assesses HF in setting of MI)
I - No HF
II - Pulmonary edema <50%, S3, SBP > 90
III - Pulmonary edema >50%, S3, SBP > 90
IV - Cardiogenic shock, SBP < 90
Target electrolyte levels for MI:
Ca++ > 1.0
K+ 4.0-5.0
Mg++ >0.8
When converting AFib, which PO cardioverting agent tends to lower BP less? Beta blockers or CCBs?
Beta Blockers.
STEMI Imposters
BER Pericarditis LBBB LVH Paced Increased ICP Aortic dissection (more likely affects RCA)
Timelines for PCI vs TNK and what study is it based on?
For PCI, door to balloon must occur < 90 minutes, or consider it if access to TNK is delayed > 2 hours.
PRAGUE/DANAMI-2
Absolute contraindications for TNK/tPA:
- Hx of ICH
- Hx of ischemic CVA < 3mo
- Known cerebral vascular lesion
- Metastatic intracranial malignancy
- Possible aortic dissection
- Active bleeding or bleeding diathesis
- Significant head/face trauma < 3mo
When is thrombolysis considered effective?
When ST segments decrease by at least 50% and ischemic symptoms are completely resolved within 90 min.
*Runs of idioventricular rhythm are highly indicative of reperfusion and successful thrombolysis. Do not treat them. They are usually self limiting.
Why do successful TNK patients still need to go for angio?
If there was 90% occluded vessel that received the thrombus, the 90% occlusion is still there after the TNK dissolves the thrombus.
Complications of untreated STEMI…
Q waves (necrosed tissue) LV wall rupture LVA Papillary muscle rupture Dysrhythmias Cardiogenic shock
Front line vasoactive therapies for cardiogenic shock:
Always start them on levophed first, then start the dobutamine. Consider milrinone only in tachycardia and extreme cases since it stays in the system for so long and is hard to correct.
There are two types of HF. Diastolic (preserved EF) and systolic (reduced EF). What must your EF be less than to be considered as systolic failure?
<40%
What does the NYHA score measure? What study suggests that an NYHA score of 4 should get ACE-Is?
Heart failure
Class 1: No symptoms
Class 2: Slight SOB/angina on physical activity
Class 3: Marked limitation on walking 20-100m. Comfortable at rest.
Class 4: Severe limitations. Symptomatic even at rest.
CONSENSUS-1
Chronic Tx for HF:
*ACE-I/ARB
*Beta blockers
*Spironolactone
TNG patch
Diuretics
CRT/ICD